ACOG MK-II Dual Lever Mount raises the ACOG by only 3/16" off the top of your rail. The mount is approx. 3 3/4" long to use up as little rail space as possible. The new MK-II Lever features a built-in precision adjustment wheel allowing fingertip (no tool) selection to desired tension to fit variations in 1913 Mil-Std dimensions. The mounts adjustment wheel comes pre-gauged and locked to the center of the Mil-Std Dovetail specs.